This invention relates to devices and methods for the resurfacing of roads, particularly gravel roads.
In the art of road resurfacing, gravel roads often need replacement gravel as the coarse material tends to migrate downward, leaving slippery mud and organic matter on the surface. Usually, additional gravel is placed on the road, and the road is then graded. Some gravel also migrates off the road, and a system has been proposed in U.S. Pat. No. 5,108,221 for returning that gravel to the road. So far as the inventor is aware, however, no system has been successfully used or proposed for the recovery of gravel in the road surface.
There is therefore provided in accordance with one embodiment of the invention, a road resurfacing device that includes a frame on which is mounted a ripper bar for ripping the road surface, preferably to a controlled depth, and behind it a separator for separating coarse and fine material in the road surface such the coarse material is deposited on fine material. The frame is supported by ground engaging supports, preferably rollers extending across the frame.
The ripper bar preferably has depending teeth in rows on both sides of the ripper bar and is rotatable so that either sets of teeth, which may be at different heights, rip the road surface.
The separator is preferably formed of ground turning discs mounted on angled shafts to direct material first to one side and then to the other. The ground turning discs preferably rotate counter to the direction of movement of the frame.
In a method of resurfacing a gravel road, there are provided the steps of ripping the surface of the gravel road to break up fine and coarse material near the surface of the gravel road; and separating coarse material from fine material such that coarse material is deposited on top of the fine material. The road may then be graded. The depth of rip is controlled to rip up gravel and not penetrate the sub-surface of the gravel road. Preferably, the ripping and separation functions are achieved by moving the road resurfacing device of the invention across a gravel road behind, in front of or under a grader or tractor.
There is also provided according to a still further aspect of the invention a method of resurfacing an icy road in which the ice is first ripped and then broken into smaller fragments. The smaller fragments may be moved to one side and removed by a grader.
These and other aspects of the invention are described in the detailed description of the invention and claimed in the claims that follow.